Machines of the shifting tray type have heretofore been provided to receive sheets of paper from a copier or printer. Such machines have involved various means for shifting the sheet inlet ends of the trays vertically past a sheet entry position so that the sheets may be fed into the receiving trays without complex sheet transport systems involving travelling belts or rollers and some form of deflector to direct sheets from the transport into the trays for collating sheets supplied from a copier or receiving collated sets of sheets from a printer, as well as for simply receiving one or more sheets in a selected tray for mailboxing or pigeon-holing the output from a copier, printer or facsimile machine.
Such machines are represented by Lawrence U.S. Pat. No. 4,343,463 and DuBois and Hamma U.S. Pat. No. 4,328,963 wherein the sheet receiving ends of the trays are successively moved by cams from closely spaced positions above and below the sheet entry location to widely spaced or separated positions at the sheet entry location. Also, sets of horizontally extended trays have been supported in a frame or cage which is vertically shifted to the sheet entry location, as shown, for example, in Shirahase U.S. Pat. No. 4,162,787.
Fazio et al U.S. Pat. No. 4,830,358 discloses a set of fixed trays into which sheets are fed by a pivotal infeed.
In addition, as seen in Lawrence U.S. Pat. No. 4,843,434, a bin opener may be employed to move vertically relative to a set of trays and open the trays to receive sheets, while the trays remain close together at other times.
Langner U.S. Pat. Nos. 4,265,445 and 4,228,070 disclose a set of fixed trays to which a sheet guide or infeed is progressively moved, and DuBois U.S. Pat. No. 4,478,406 shows such a sorter in which the trays are sequentially spread apart to enhance sheet entry.